Magnetic tracking systems use magnetic fields to determine the location and orientation of an object within a given region. A sensor is positioned on the object (e.g., a piece of equipment or a human body) to detect magnetic fields present within the given region. From the detected field information, a computer system may compute the location and orientation of the object with respect to a reference coordinate system. These systems are useful, for example, in the medical field, for tracking instruments associated with medical procedures thereby facilitating advanced methods in surgery and diagnostics.